TY - JOUR
T1 - Photonic-structured TCO front contacts yielding optical and electrically enhanced thin-film solar cells
AU - Sanchez-Sobrado, Olalla
AU - Mendes, Manuel J.
AU - Mateus, Tiago
AU - Costa, João
AU - Nunes, Daniela
AU - Águas, Hugo
AU - Fortunato, Elvira
AU - Martins, Rodrigo
N1 - COMPETE 2020 Programme and National Funds through FCT (Portuguese Foundation for Science and Technology) under the projects UID/CTM/50025/2019.
ALTALUZ ( PTDC/CTM-ENE/5125/2014 ).
SuperSolar (PTDC/NAN-OPT/28430/2017).
TACIT (PTDC/NAN-OPT/28837/2017).
LocalEnergy (PTDC/EAM-PEC/29905/2017).
grant SFRH/BPD/114833/2016 .
PY - 2020/1/15
Y1 - 2020/1/15
N2 - Wavelength-structured transparent conductive oxide (TCO) electrodes are highly promising to improve both the optical and electrical performance of photovoltaic (PV) devices, due to wave-optical light-trapping (LT) effects and higher TCO volume without increasing optical losses. Herein we present a complete study of the benefits of microstructured IZO contacts applied on amorphous-silicon (a-Si) thin film solar cells. The IZO LT structures were integrated by an innovative colloidal lithography process on the front contact of the cells, resulting in enhancements of 26.7% in photocurrent, with respect to planar reference cells, when using an ultra-thin (30 nm) flat IZO layer between the LT structures and the a-Si absorber. However, the best efficiency enhancement (23.1%) was attained with an optimized thickness of 190 nm for this layer, due to a more favorable combination of optical and electrical gains. In view of the application of this LT strategy in flexible PV devices operating under bending, the angular response of the cells was studied for 0-90° incidence angles. This showed that the LT enhancements are generally higher at oblique incidence, reaching 53.2% and 52%, respectively in photocurrent and efficiency, at ± 70° angles with the optimized flat IZO thickness of 190 nm; and 52.2% in efficiency at ± 40° with the ultra-thin thickness of 30 nm. These results are among the highest gains reported thus far for LT-enhanced thin film solar cells.
AB - Wavelength-structured transparent conductive oxide (TCO) electrodes are highly promising to improve both the optical and electrical performance of photovoltaic (PV) devices, due to wave-optical light-trapping (LT) effects and higher TCO volume without increasing optical losses. Herein we present a complete study of the benefits of microstructured IZO contacts applied on amorphous-silicon (a-Si) thin film solar cells. The IZO LT structures were integrated by an innovative colloidal lithography process on the front contact of the cells, resulting in enhancements of 26.7% in photocurrent, with respect to planar reference cells, when using an ultra-thin (30 nm) flat IZO layer between the LT structures and the a-Si absorber. However, the best efficiency enhancement (23.1%) was attained with an optimized thickness of 190 nm for this layer, due to a more favorable combination of optical and electrical gains. In view of the application of this LT strategy in flexible PV devices operating under bending, the angular response of the cells was studied for 0-90° incidence angles. This showed that the LT enhancements are generally higher at oblique incidence, reaching 53.2% and 52%, respectively in photocurrent and efficiency, at ± 70° angles with the optimized flat IZO thickness of 190 nm; and 52.2% in efficiency at ± 40° with the ultra-thin thickness of 30 nm. These results are among the highest gains reported thus far for LT-enhanced thin film solar cells.
KW - Amorphous silicon solar cells
KW - Angular response of light trapping
KW - Photonic-structured transparent electrodes
KW - Thin film photovoltaics
KW - Wave-optical light management
UR - http://www.scopus.com/inward/record.url?scp=85076254591&partnerID=8YFLogxK
U2 - 10.1016/j.solener.2019.11.051
DO - 10.1016/j.solener.2019.11.051
M3 - Article
AN - SCOPUS:85076254591
VL - 196
SP - 92
EP - 98
JO - Solar Energy
JF - Solar Energy
SN - 0038-092X
ER -
